Anti-fog surgical face mask

ABSTRACT

A surgical face mask which comprises a filtration medium and an air impervious element secured to the upper portion of the mask. The impervious element functions to prevent moist breath from rising over the upper portion of the mask and fogging eyeglasses of the wearer of the mask. The mask may also bear impervious elements around all the edges thereof.

United States Patent 11 1 Lauer 1 1 ANTI-FOG SURGICAL FACE MASK [75]Inventor: William Lauer, Madison, NJ.

[73] Assignee: Johnson & Johnson, New

Brunswick, NJ.

221 Filed: Nov. 1,1973

211 App]. No.: 411,873

52 u.s.c1 128/146.2; 128/139 51 1111.0. .4611 9/04 58 Field of Search128/1462, 145.3, 146.4,

123/1465, 146.6, 146, 142.4, 136, 132 D, 163; 2/14 K, 9 R, 206

[56] References Cited UNITED STATES PATENTS 2,012,505 3 1935 Goldsmith128/1462 2,081,779 5/1937 Titus............. 2,655,656 10/1953 Moeller2,762,368 9/1956 Bloomfield 128/1466 1451 June 10, 1975 3,049,121 8/1962Brumfield et a1. 128/1462 FOREIGN PATENTS OR APPLICATIONS 893,614 4/1962United Kingdom 128/1462 967,455 8/1964 United Kingdom 128/1462 94,480l/l963 Denmark 128/1462 506,221 5/1939 United Kingdom 128/139 PrimaryExaminerRichard A. Gaudet Assistant Examiner-Henry J. Recla [57]ABSTRACT A surgical face mask which comprises a filtration medium and anair impervious element secured to the upper portion of the mask. Theimpervious element functions to prevent moist breath from rising overthe upper portion of the mask and fogging eyeglasses of the wearer ofthe mask. The mask may also bear impervious elements around all theedges thereof.

16 Claims, 16 Drawing Figures PATENTED JUN I 0 I975 SHEET SHEETPATENTEDJUH l 0 I975 as F -F 1 ANTI-FOG SURGICAL FACE MASK BACKGROUND OFTHE INVENTION Surgical face masks have been employed for some time bythe operating room staff during surgical procedures. The purpose of theface mask is to prevent bacteria exhaled by the surgeon, or other of theoperating room staff, from contaminating the patient undergoing surgery.The face masks contain a filter medium which is of sufficiently smallpore size to prevent bacteria from flowing through the mask.

A potential problem connected with the use of surgical face masks existsin situations where the surgeon, or other of the room staff, wearseyeglasses. The exhaled breath of the wearer is usually warmer and moremoist than the surrounding air, and, when it rises upwardly from themask, has a tendency to fog eyeglasses. This is a very annoying andpotentially dangerous situation as, for example, the surgeon must delayhis surgical procedure in order to clear the eyeglasses so that his fullvision can be restored. This problem has become more significant inrecent years because the filtration ability of face masks has increased.Older surgical face masks, which were made of folded squares of linen orgauze, had relatively low air resistance and were poor bacteria filters.Current face masks are extremely good bacteria filters but generallyhave higher air resistance than the older masks. As the air resistanceof a mask increases, there is an increased tendency for air beingexhaled by the wearer to escape at the top of the mask. As noted, thisair is generally warmer and more moist than the surrounding air, so thatthere is a tendency of the moisture therein to condense on theeyeglasses worn by surgeons and other operating room staff.

Air resistance," as used herein, is a measure of the resistance to airflow through the mask. Air resistance is determined by measuring thepressure drop across the mask when the mask is placed in a stream of airflowing at a rate of 85 cubic feet per minute. Air resistance isconsidered to be low" when the pressure drop is less than about 0.03inches of water. Air resistance is considered to be high when thepressure drop exceeds about 0.45 inches of water. Masks having pressuredrops between about 0.30 and about 0.45 inches of water are consideredto have intermediate air resistance.

SUMMARY OF THE INVENTION I have now discovered a relatively simplemethod of preventing eyeglass fogging without any substantail decreasein the bacteria filtering efficiency of a mask. I accomplish this resultby employing an air impervious element on at least the upper portion ofthe mask. The air impervious element may be placed only on the outersurface of the mask or only on the inner surface of the mask.Alternatively, the mask may have an air impervious element overlyingboth its inner and outer surfaces. As a variation of the latterarrangement, a single air impervious element may be used to cover notonly the inner and outer surfaces, but also the top edge of the mask. Instill another arrangement, the air-impervious element may be disposedwithin the main body of the face mask. The air-impervious elementprevents exhaled breath from moving upwardly from the upper portion ofthe mask and fogging the wearers eyeglasses. Thus, according to thepresent invention, there is provided a surgical face mask comprising abody portion having upper and lower parts, said body portion comprisinga filtration medium for filtering bacteria, means for securing the maskover the mouth and nose of the wearer, and an air impervious elementacross the upper part of said body portion.

In another embodiment of the invention, an air impervious element isprovided on both the inner and outer surfaces of the upper part of themask. Preferably, in this embodiment, a single piece of the airimpervious material is used, that is, the air impervious materialoverlies the outer surface of the mask, is folded over the uppermostedge of the face mask and is continued downwardly over the inner surfaceof the mask.

In a preferred embodiment, the top, bottom, and side peripheries of theinner surface of the mask have thin, elongated strips of air imperviousmaterial secured thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood with reference to the annexed drawings in which:

FIG. I is a view of a first embodiment of the mask of this inventionshown in position on the face of a wearer.

FIG. 2 is a plan view showing the outer surface of the mask of FIG. 1.

FIG. 3 is a plan view showing the inner surface of the mask of FIG. 1.

FIG. 4 is a cross sectional view taken along line 44 of FIG. 2.

FIG. 5 is a side view, partially in section, showing the mask of FIG. Iin position on the face of a wearer.

FIG. 6 is a plan view showing the outer surface of a second embodimentof the mask of the invention.

FIG. 7 is a plan view showing the inner surface of the mask of FIG. 6.

FIG. 8 is a cross sectional view taken along line 88 of FIG. 6.

FIG. 9 is a side view, partially in section and with certain portionsenlarged, of a third embodiment of the mask of this invention shown inposition on the face of a wearer.

FIG. 10 is a plan view showing the outer surface of a fourth embodimentof the mask of the present invention.

FIG. 11 is a plan view showing the inner surface of the mask of FIG. 10.

FIG. 12 is a cross sectional view, with parts broken away, taken alongline 12-12 of FIG. 11, at an enlarged scale.

FIG. 13 is a cross sectional view, with parts broken away, taken alongline I3l3 of FIG. 11, at an enlarged scale.

FIG. 14 is a perspective view of the outer surface of a preformed,contoured face mask embodying the present invention.

FIG. 15 is a perspective view of the inner surface of another preformed,contoured face mask, similar to that shown in FIG. 14, embodying thepresent invention.

FIG. I6 is a cross-sectional view taken along the lines 16-16 of FIG.15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may beemployed in a flat face mask such as those shown in FIGS. 1-13 or in apre formed contoured mask such as those shown in FIGS.

14-16. A flat mask has a body portion which has two major surfaces,i.e., an inner major surface and an outer major surface, and comprises asuitable filtration medium. The body portion may include, if desired, afacing material disposed on one or both major surfaces of the filtrationmedium. A flat face mask may be pleated or unpleated, as desired.

The terms outside and outer surface," as used herein, refer to thatportion, or surface, respectively, of the mask (or of any elementthereof) which is disposed away from the face of the wearer when themask is in place; the terms inside" and inner surface" refer to thatportion, or surface, respectively, of the mask (or of any elementthereof) which contacts or is disposed toward the face of the wearerwhen the mask is in place. The term upper, as used herein, refers tothat part of the mask (or of any element thereof) which is nearer thenose and eyes of the wearer when the mask is in place; the term lowerrefers to that part of the mask (or of any element thereof) which isnearer the chin of the wearer when the mask is in place.

Referring now to FIG. 1, there is illustrated, on the face of a wearer,a first embodiment of the face mask of the present invention. Face mask20 includes a body portion 21 which has a binding 24 along its upperedge and a binding 25 along its lower edge. Body portion 21 also hasbindings 23 along the side edges thereof which bindings may be extendedat the corners of the mask, if desired to provide tie strings 28 whichmay be tied at the back of the head of the wearer as shown at 26 of FIG.1 in order to secure the mask in its desired position. As is well knownin the art, side bindings 23 and tie strings 28 may comprise biasedfabric tapes and may, if desired, have elastic characteristics. Theupper, outer surface of body portion 21 carries an air imperviouselement which comprises a thin film or sheet of suitable plastic such aspolyethylene, polypropylene, poly(vinyl chloride), orpoly(ethylene-vinyl acetate). The upper portion of mask 20 carries anose clip 27 which may be formed, for example, from a thin strip ofaluminum.

The first embodiment of the present invention will now be described ingreater detail with reference to FIGS. 2, 3 and 4 of the drawings.

Referring particularly to FIG. 2, main body portion 21 is folded to formpleats 29 which unfold to better conform the mask to the face of thewearer when the mask is put on. As indicated, in order to preventexhaled breath of the wearer of the mask from rising and fogging hiseyeglasses, mask 20 is provided with an air impervious element 30 whichis disposed across the upper outer surface of the mask. Air imperviouselement 30 may be secured to body portion 21 by any suitable securingmeans, The securing means may be employed in a thin line or band alongthe upper and side peripheries of air impervious element 30, or in apattern over the entire air impervious element, or in continuousover-all coating. 1n the embodiment of FIG. 2, it will be seen that theupper periphery of airimperivous element 30 is secured to upper binding24. The side peripheries of element 30 are disposed between main bodyportion 21 and side bindings 23 and are held in place by stitchingindicated by dotted line 18.

When, as shown in FIGS. 2 and 4, air impervious element 30 is securedonly along its upper and side peripheries, only a very small percentageof its total surface area is in sealing engagement with main bodyportion 21; as a result, impervious element 30 is free to act as a flapwhich deflects exhaled breath downwardly away from the eyes of thewearer. This flap-like arrangement is illustrated in the upper righthand portion of FIG. 4 which also shows element 30 overlying nose clip27 and the outer surface of body portion 21. At the same time, however,element 30 is free to move outwardly from the surface of the mask, forexample, under the stress applied by exhaled breath. It has also beenfound that mask 20 functions to prevent fogging of eyeglasses even wheremost, or substantially all, of the surface area of impervious element 30is in sealing engagement with main body portion 21. Any desired meansmay be used to secure impervious element 30 to the outer surface of mainbody portion 21 in the desired manner, These means would include, forexample, stitching and heat sealing, and use of the wellknown water orsolvent-based adhesives, such as a plasticized polyvinyl acetate resindispersion.

Main body portion 21 includes a filtration medium for filteringbacteria. The filtration medium may be formed from fibers such as, forexample, fiberglass, polyester, polypropylene, vinyon fibers and similarmaterials, used alone or in combination. Body portion 21 may alsoinclude a facing material, e.g., a nonwoven fabric, on one or both ofits major surfaces.

As indicated earlier, air impervious element 30 may comprise a film ofplastic material such as polyvinyl chloride, polyethylene, polypropyleneand poly(ethylenevinyl acetate). Alternatively, element 30 may be anon-woven fabric or paper type material having substantially greaterresistance to air flow than the filtration medium and facing material.When a material is described herein as being air impervious it is meanteither that the material substantially completely resists the flow ofair or other gas therethrough (as, for example, a film of polyethylene)or that the material has a substantially greater resistance to the flowof air than the filtration medium and facing material. It will beunderstood that, generally speaking, any thin flexible material that issubstantially resistant to air flow can be employed in the practice ofthis invention. 1f plastic film is selected for impervious element 30,its thickness should be from about 0.5 mil to about 5.0 mils, preferablyfrom about 0.75 mil to about 1.5 mils. If a nonwo ven fabric is used forimpervious element 30, its thickness should be approximately 3-15 mils,preferably from about 5 mil to about l0 mils.

The inner surface of the first embodiment, seen in FIG. 3, carriesbindings 23, 24, 25 which are merely folded-over portions of thecorresponding bindings on the outer surface of the mask. The foldedbindings are secured to body portion 21 by stitching, indicated bydotted lines 18 in FIGS. 2 and 3. It will be seen that the inner surfaceof the first embodiment carries no impervious element. l have observedalso that fogging of eyeglasses is prevented when the impervious elementis disposed on the inner surface of main body portion 21. When theimpervious element 30 is on the inner surface, it is effective when itis disposed in either the preferred flap-like" arrangement previouslydescribed, or in an arrangement wherein a great portion, or even all, ofits surface area is in sealing engagement with the inner surface of mainbody portion 21.

Referring to FIG, 5, there is shown a side view, partially in section,of the mask of FIGS. 1-4 in position on the face of the wearer. FIG. 5shows that element 30 is secured, at its upper periphery, to binding 24of mask 20. The remaining part of element 30, except for the sideperipheries thereof, overlies noseclip 27 and the outer surface of themask to form the flap-like arrangement already discussed.

A second embodiment of the present invention will be described withreference to FIGS. 6, 7 and 8 of the drawings. Mask 40 includes a mainbody portion 41, upper binding 44, lower binding 45, side bindings 43,noseclip 47, tie strings 48, and pleats 49. The outer surface of mask40, as shown in FIG. 6, has an air impervious element 50 disposed overthe upper outer surface of main body portion 41. As illustrated in FIGS.7 and 8, impervious element 50 is folded over upper binding 44 at theuppermost edge of body portion 41 and is continued downwardly for adistance along the inner surface of the mask. Element 50 is held inposition by securing it, along its side edges, to both the inner andouter side peripheries of the mask. If desired, element 50 can befurther held in position by securing it along the upper periphery of themask but this is not necessary, and preferably is not done. Asillustrated in FIG. 8, when element 50 is arranged, in the manner justdescribed, so that part thereof overlies the outer surface of the maskand part thereof overlies the inner surface of the mask, there areformed two flap-like structures. When the mask is in place, the portionof element 50 that is disposed over the inner surface of the maskcontacts the face of the wearer.

As the wearer breathes, element 50, because of its flap-like structureand due to the presence of face moisture (especially in the case ofplastic), stays in contact with the face of the wearer thus preventingthe upward escape of moist air between the face and the mask. At thesame time, the flap-like structure allows main body portion 41 to moveforwardly (i.e., away from the face of the wearer) under the stress ofthe exhaled breath. Any moist breath which does not pass directlythrough the filter medium is prevented from escaping upwardly betweenimpervious element 50 and main body portion 41 by the folded-overportion of element 50. Thus, it is seen that moist air is prevented fromreaching. and subsequently fogging, the eyeglasses of the wearer.

An alternative arrangement of the air-impervious element is shown in theembodiment illustrated in FIG. 9. As seen in the enlarged portion ofFIG. 9, the body portion of the mask includes a filtration medium 35 andfacing material 36. An air-impervious element 37 is positioned over partof both major surfaces of filtration medium 35 and is itself covered byfacing material 36. Thus, in this particular embodiment, it will be seenthat the air impervious element is disposed within the body portion ofthe mask. Upper binding 38 overlies facing material 36 at the upperportion of the mask, and noseclip 39 is attached, in its desiredposition, to the facing material. Although the arrangement of FIG. 9does not allow for the loose flap, it does adequately perform thefunction of preventing eyeglass fogging in a large number of instances.

Although eyeglass fogging by exhaled breath which passes upwardly of themask can be prevented by placing a substantially air impervious elementon the upper portion of the face mask, it is also recognized thatexhaled breath may leak around the side edges of an improperlypositioned mask. To further assure prevention of such leaks, thestructure shown in the mask illustrated in FIGS. 10l3 may be employed.Referring to FIG. 10, pleated face masks comprises a main body portion6], side bindings 63, an upper binding 64, a lower binding 65, a noseclip 67 and tie strings 68, corresponding to the analogous parts of theembodiments already discussed. Upper binding 64 and lower binding 65 aresecured to body portion 61 by stitching (not illustrated) although asuitable adhesive or other securing means may be used if desired.Referring to FIGS. 10, 11 and 13, air impervious element is disposedover the upper outer surface of body portion 61, folded over upperbinding 64, and continued downwardly over the inner surface of the mask.An elongated, thin strip 76 of air impervious material is heat sealedalong its lowermost edge to binding 65. At the corners of the mask, sidebindings 63 overlie the ends of strip 76 and the ends of that portion ofimpervious element 7 which extends downwardly over the inner surface ofthe mask. The side bindings are secured by stitching (not illustrated)which also serves at the same time to attach air impervious element 70to body portion 61. As best seen in FIG. 11, strips of imperviousmaterial are heat sealed to side bindings 63 at the side peripheries ofthe mask. Since air impervious element 70 is attached to body portion 61only by means of the stitching that holds side bindings 63 in place, airimpervious element 70 is free to act as a flap," that is, air imperviouselement 70 can move more or less independently of body portion 61, onboth the inner and outer surfaces of the mask, as air is inhaled andexhaled by the wearer. This flap-like construction is illustrated in theupper part of FIG. 13 where air impervious element 70 is shown spacedaway from body portion 6] on both the inner and outer surfaces of themask. Likewise, since lower strip 76 and side strips 75 of airimpervious material are attached only at the peripheries of the mask,they also are free to move more or less independently of the rest of themask. Thus, it will be seen that on the inner surface of the mask, lowerstrip 76, side strips 75, and the folded over portion of air imperviouselement 70 are all attached to the mask in the flap like constructionjust described. It has been observed, especially in the case where theair impervious strips comprise a plastic such as polyethylene, that theair impervious elements on the inner surface of the mask tend to clingto the face of the wearer when he exhales. This clinging to the face bythese air impervious elements forms a seal which prevents exhaled breathfrom escaping around the edges of the mask. Due to the flap-likeconstruction, body portion 6] of the mask can move away from thewearer's face without breaking the aforementioned seal. Air imperviouselement 70, due to its folded over arrangement on the upper part of themask tends to direct any exhaled breath that does not pass through thefilter medium over the top edge of binding 64 and then downwardly overthe outer surface of the mask so that eyeglass fogging is effectivelyprevented.

Although in FIGS. 12 and 13, impervious element 70 is shown as a singlesheet folded over the uppermost edge of the face mask it will beunderstood that it is also possible to employ separate pieces of plasticon the outer and inner surfaces of the body portion of the face mask, ifso desired.

As indicated in the accompanying drawings, the several imperviouselements are sufficiently long to reach from one side of the mask to theother, or from the upper edge to the lower edge thereof as the case maybe. In their folded condition, most commercially available pleated facemasks measure about 3% to 4 inches from their upper edge to their loweredge. In the embodiment illustrated in FIGS. 2-4, I have found thatimpervious element 70 is most effective in preventing eye glass foggingwhen it extends downwardly from the top of the mask a distance of fromabout 1% inches to about 2% inches. In certain circumstances, imperviouselement 70 may be effective to reduce or eliminate eye glass foggingwhen it extends less than 1% inches from the top edge of the mask. Inthe modified embodiment of FIGs. 2-4, that is, where the imperviouselement is attached only to the inner surface of the upper portion ofthe mask, it is preferable that the impervious element extend downwardlyfrom the top of the mask a distance of at least about three-eighths ofan inch in order to effectively prevent the escape of moist air betweenthe upper edge of the mask and the face of the wearer. correspondingly,in the embodiment shown in FIGS. 6-8, impervious element extendsdownwardly on the outer surface of the mask for a distance of from about1 /4 inches to about 2 /2 the folded-over portion of impervious element50 extends downwardly over the inner surface of the mask a distance ofat least about three-eighths of an inch. In the embodiment shown inFIGS. 10-13, air impervious element has dimensions which correspond tothose given above for impervious element 50 in the embodiment of FIGS.6-8. The width of impervious strips and 76 should be about one-half inchalthough this dimension may be varied under certain circumstances.

The present invention may also be employed in a preformed surgical facemask as illustrated in FIGS. 14-16. In FIG. 14, preformed, contouredmask 85 has a main body 80 which is usually formed from a thermoplasticfibrous material, such as polyester, Vinyon (co polymers of vinylchloride and vinyl acetate) or suitable blends of these fibers withrayon, into its desired preformed, contoured shape. Mask has an elastictie string 8I which is used to secure the mask over the nose and mouthof the wearer. The upper portion of the mask carries a nose clip 82. Theupper, outer surface of the mask has disposed thereover a strip 83 of anairimpervious material which is cut in such fashion that it willsubstantially conform to the upper surface of the mask. Strip 83 acts inthe manner already described to prevent exhaled breath from flowingacross the surface of the mask toward the eyeglasses of the wearer. Themask will be effective in preventing fogging of eyeglasses if the entiresurface area of strip 83 is adhered to the main body of the mask.Preferably, however, strip 83 is secured at the peripheral edges of themask in order to provide a flap-like construction analogous to thatdiscussed for the flat face masks. Either of the above described methodsfor securing strip 83 to main body 80 will provide a face mask that willeffectively reduce or even eliminate eyeglass fogging.

In an alternative embodiment illustrated in FIGS. 15 and 16, contouredmask has a body portion 90, a nose clip 92, and an air imperviouselement 93, corresponding respectively to parts 80, 82, and 83 of themask shown in FIG. 14. Mask 95 also has a strip 96 of imperviousmaterial along the edge of its inner surface as seen in FIG. IS. Theentire surface area of strip 96 may be bonded to the inner surface ofmain body 90,

for example, by the use ofa suitable adhesive. Preferably, however,strip 96 is secured by heat sealing, stitching, or gluing the edgesthereof to the inner surface of the mask as indicated by dotted line 98of FIG. 15, to provide a flap-like arrangement analogous to that shownin the upper portion of FIG. 16. The presence of strip 96 on the innersurface of the mask substantially eliminates the escape of moist airalong the area where the mask contacts the face of the wearer andreduces even further the possibility of eyeglass fogging. Imperviousstrip 96 should be about one-half inch in width.

It will be understood by those skilled in the art that the principles ofthe present invention may be applied not only to the pleated face masksillustrated in FIGS. 1-13 and to the contoured face masks of FIGS.14-16, but also to other face masks such as unpleated face masks and towhat are known in the art as pouch or pocket" type face masks. Othervariations and modifications can be made without departing from thespirit and scope of the invention.

What is claimed is:

l. A surgical face mask comprising:

a. a body portion having an upper part, a lower part, an upper edge, alower edge and a pair of side edges and comprising a filtration mediumfor filtering bacteria;

b. means for securing the mask over the mouth and nose of the wearer;and

c. a sheet of air impervious material having an upper edge, a loweredge, and a pair of side edges, the upper edge of said air imperviousmaterial being secured to the upper part of said body portion, the loweredge of said air impervious material lying between said upper and loweredges of said body portion and being substantially free from attachmentto said body portion, said sheet of air impervious material extendingsubstantially from side to side of said body portion whereby, when themask is worn, exhaled breath is directed downwardly from the upper partof the mask and away from the eyes of the wearer.

2. A face mask according to claim 1 wherein said sheet of air imperviousmaterial is attached to the outer surface of said body portion.

3. A face mask according to claim 2 wherein said sheet of air imperviousmaterial is folded over the uppermost edge of the mask and is continueddownwardly for a relatively short distance along the inner surface ofthe mask.

4. A face mask according to claim 2 wherein a second sheet of airimpervious material is attached to the upper inner surface of said bodyportion.

5. A face mask according to claim I wherein said sheet of air imperviousmaterial is disposed within said body portion.

6. A face mask according to claim 3 wherein said sheet of air imperviousmaterial is attached to the upper inner surface of said body portion.

7. A face mask according to claim 4 wherein elongated narrow strips ofair impervious material are secured to the side and bottom edges of theinner surface of the mask.

8. A face mask according to claim 1 wherein said sheet of air imperviousmaterial is a plastic film.

9. A face mask according to claim I wherein said sheet of air imperviousmaterial is a nonwoven fabric.

10. A face mask according to claim 1 wherein said sheet of airimpervious material is paper.

11. A face mask according to claim 1 wherein said body portion iscontoured.

12. A face mask according to claim 1 wherein said body portion furthercomprises an air pervious facing material.

13. A face mask according to claim 1 further comprising a noseclip.

14. A face mask according to claim 13 wherein said body portion includesa facing material overlying both major surfaces of said filtrationmedium.

15. A surgical face mask comprising:

a. a body portion having an upper part, a lower part, an upper edge, alower edge and a pair of side edges and comprising a filtration mediumfor filtering bacteria;

b. means for securing the mask over the mouth and nose of the wearer;and

c. a sheet of air impervious material having a lower edge and a pair ofside edges, said air impervious material being secured to the upper partof said body portion, the lower edge of said air impervious materiallying between said upper and lower edges of said body portion and beingsubstantially free from attachment to said body portion, said sheet ofair impervious material being folded over the uppermost edge of the maskand continued downwardly for a relatively short distance along the innersurface of the mask whereby, when the mask is worn, exhaled breath isdirected downwardly from the upper part of the mask and away from theeyes of the wearer.

16. A surgical mask according to claim 15 further comprising elongatedstrips of air impervious material secured to the side and bottom edgesof the inner surface of aaid body portion.

1. A surgical face mask comprising: a. a body portion having an upperpart, a lower part, an upper edge, a lower edge and a pair of side edgesand comprising a filtration medium for filtering bacteria; b. means forsecuring the mask over the mouth and nose of the wearer; and c. a sheetof air impervious material having an upper edge, a lower edge, and apair of side edges, the upper edge of said air impervious material beingsecured to the upper part of said body portion, the lower edge of saidair impervious material lying between said upper and lower edges of saidbody portion and being substantially free from attachment to said bodyportion, said sheet of air impervious material extending substantiallyfrom side to side of said body portion whereby, when the mask is worn,exhaled breath is directed downwardly from the upper part of the maskand away from the eyes of the wearer.
 2. A face mask according to claim1 wherein said sheet of air impervious material is attached to the outersurface of said body portion.
 3. A face mask according to claim 2wherein said sheet of air impervious material is folded over theuppermost edge of the mask and is continued downwardly for a relativelyshort distance along the inner surface of the mask.
 4. A face maskaccording to claim 2 wherein a second sheet of air impervious materialis attached to the upper inner surface of said body portion.
 5. A facemask according to claim 1 wherein said sheet of air impervious materialis disposed witHin said body portion.
 6. A face mask according to claim3 wherein said sheet of air impervious material is attached to the upperinner surface of said body portion.
 7. A face mask according to claim 4wherein elongated narrow strips of air impervious material are securedto the side and bottom edges of the inner surface of the mask.
 8. A facemask according to claim 1 wherein said sheet of air impervious materialis a plastic film.
 9. A face mask according to claim 1 wherein saidsheet of air impervious material is a nonwoven fabric.
 10. A face maskaccording to claim 1 wherein said sheet of air impervious material ispaper.
 11. A face mask according to claim 1 wherein said body portion iscontoured.
 12. A face mask according to claim 1 wherein said bodyportion further comprises an air pervious facing material.
 13. A facemask according to claim 1 further comprising a noseclip.
 14. A face maskaccording to claim 13 wherein said body portion includes a facingmaterial overlying both major surfaces of said filtration medium.
 15. Asurgical face mask comprising: a. a body portion having an upper part, alower part, an upper edge, a lower edge and a pair of side edges andcomprising a filtration medium for filtering bacteria; b. means forsecuring the mask over the mouth and nose of the wearer; and c. a sheetof air impervious material having a lower edge and a pair of side edges,said air impervious material being secured to the upper part of saidbody portion, the lower edge of said air impervious material lyingbetween said upper and lower edges of said body portion and beingsubstantially free from attachment to said body portion, said sheet ofair impervious material being folded over the uppermost edge of the maskand continued downwardly for a relatively short distance along the innersurface of the mask whereby, when the mask is worn, exhaled breath isdirected downwardly from the upper part of the mask and away from theeyes of the wearer.
 16. A surgical mask according to claim 15 furthercomprising elongated strips of air impervious material secured to theside and bottom edges of the inner surface of aaid body portion.